Tips and service charges are usually not automatically added to a bill in the United States (except when your party is over six people). If service is satisfactory, customers generally give wait staff, taxi drivers, barbers, hairdressers, and so forth, a tip of from 15% to 20% of the total bill. (Be aware that tipping wait staff less than 15% is considered a sign that service was bad.) Bellhops, doormen, and porters at airports and railway stations are generally tipped $1 for each item of luggage. In Seattle there is no recognized system for tipping concierges. A gratuity of $2-$5 is suggested if you have the concierge arrange for a service such as restaurant reservations, theatre tickets, or car service, and $10-$20 if the service is more extensive or unusual, such as having a large bouquet of roses delivered on a Sunday.